Imperato, Giovanni and Vasold, Rudolf and Koenig, Burkhard (2006) Stille reactions with tetraalkylstannanes and phenyltrialkylstannanes in low melting sugar-urea-salt mixtures. ADVANCED SYNTHESIS & CATALYSIS, 348 (15). pp. 2243-2247. ISSN 1615-4150, 1615-4169
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The transfer of simple alkyl groups in Stille reactions usually requires special solvents (HMPA) or certain organotin reagents (stannatranes, monoorganotin halides) to be efficient. Using low-melting mixtures of sugar, urea and inorganic salt as solvent, a fast and efficient palladiumcatalyzed alkyl transfer with tetraalkyltin reagents was observed. The high polarity and nucleophilic character of the solvent melt promotes the reaction. Stille biaryl synthesis using electron-poor and electron-rich aryl bromides proceeds with quantitative yields in the sugar-urea-salt melt. Catalyst loading may be reduced to 0.001 mol % and the catalyst melt mixture remains active in several reaction cycles. Showing the same or improved performance for Stille reactions than organic solvents and allowing a very simple work up, sugar-urea-salt melts are a non-toxic and cheap alternative reaction medium available in bulk quantities for the catalytic process.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | CATALYZED COUPLING REACTIONS; IONIC LIQUIDS; HALIDES; REAGENTS; ARYL; ORGANOSTANNANES; SOLVENTS; carbohydrates; green chemistry; palladium; Stille coupling; turnover number |
| Subjects: | 500 Science > 540 Chemistry & allied sciences |
| Divisions: | Chemistry and Pharmacy > Institut für Organische Chemie > Lehrstuhl Prof. Dr. Burkhard König |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 20 Jan 2021 11:16 |
| Last Modified: | 20 Jan 2021 11:16 |
| URI: | https://pred.uni-regensburg.de/id/eprint/33898 |
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